Blazer Value?

[Bob Q]

I came across an '85 K5 Blazer that has been in the same family since new. It's a Silverado and has a 6.2L diesel with a Banks turbo. It's all stock and hasn't really been altered at all. It's weathered some, but hasn't been abused by any means. I know it's tough to judge without a picture, but what are the rough values of something like this? Seems like I see them online going for between $10,000 and $30,000. This one is located in California.

Thanks.